JP4130402B2 - High concentration sludge treatment equipment using soil cement wall. - Google Patents

Description

  The present invention relates to a high-concentration sludge treatment apparatus using a soil cement wall that is used to treat high-concentration sludge such as livestock excreta discharged from livestock facilities.

  High-concentration sludge such as livestock excreta discharged from livestock facilities such as piggeries and cowsheds is now widely recognized as having an impact on the environment, and countermeasures have become an urgent issue. The amount of livestock excrement that is recycled as useful materials such as fertilizer is very small, and most of them require reduction by sludge treatment.

  The treatment of high-concentration sludge such as livestock excreta is generally performed in such a manner that the sludge volume is reduced by an activated sludge method that passes through a plurality of treatment tanks in which microorganisms are propagated as shown in FIG. 11 (see Patent Document 1). ). The residue is composted and reused, but sludge may remain.

In the conventional livestock manure treatment system shown in Fig. 11, sludge discharged from a piggery or a cowshed is once accumulated in an accumulation tank, then transferred to a primary sludge treatment tank, and several times from the primary treatment tank by the activated sludge method. The high-concentration sludge is treated by passing through the treatment tank. This sludge treatment apparatus is conventionally constructed in the underground with a reinforced concrete structure (see Patent Document 2).
Japanese Patent Laid-Open No. 7-327535 JP 7-8991 A

  The construction of the reinforced concrete sludge treatment equipment is expensive and requires a lot of cost for operation and maintenance, but the livestock farmers who actually discharge livestock excreta are often small, It is difficult for livestock farmers to raise the construction costs for sludge treatment equipment.

  FIGS. 12- (a) to (f) show general steps in the case of constructing a sludge treatment device made of reinforced concrete.

  At the septic tank construction site, excavation is first performed. At this time, in the case of good ground where the groundwater level is low and the excavation surface is self-supporting, as shown in (a), the excavation surface is attached with a method (inclination) and excavation is required, so that it is necessary to stop the mountain. The excavation work cost is relatively low because it can be excavated without any problems. However, if the groundwater level is high or the ground is soft, it will be expensive because it is indispensable.

  After excavation, the bottom of the excavation is laid with gravel as shown in (b) and cast concrete, as shown in (c), rebar reinforcement and formwork assembly, as shown in (d) In the state where the formwork is reinforced, the ready-mixed concrete is placed, and after the concrete exhibits a predetermined strength as shown in (e), the formwork is removed, and as shown in (f), the excavation surface and sludge treatment The construction of the sludge treatment equipment is completed by refilling the soil with the tank.

  In this way, when the sludge treatment equipment is constructed with reinforced concrete, it often requires excavation work with mountain retaining, and in addition to the cost of excavation work being high, the wall of the septic tank is made of reinforced concrete. In addition, the construction cost of the sludge treatment apparatus main body is high because many processes such as bar arrangement, formwork, and concrete placement are required.

  In view of the above background, the present invention proposes a sludge treatment apparatus that can be constructed at a lower cost than a reinforced concrete structure.

  In the present invention, the wall occupying a large part of the sludge treatment apparatus is constructed of soil cement that can also serve as a retaining wall, thereby eliminating the need for the retaining wall when constructing with reinforced concrete and reducing the material cost. This makes it possible to construct a sludge treatment device at a low cost.

  Here, when using the soil cement for the wall of the sludge treatment equipment, the weakness of the soil cement being prone to cracking in the atmosphere and being easily deteriorated in a short time due to weathering. It is necessary to overcome.

  Since soil cement is made from raw soil, it has a higher moisture content than mortar and concrete after hardening, and the structure is more porous than concrete. Therefore, when exposed to the atmosphere, moisture tends to evaporate and the amount of drying shrinkage increases, so that if a structure is exposed to the atmosphere, cracks are likely to occur. In addition, crack growth due to repeated drying shrinkage and wet and dry with rainwater, deterioration of turtle shell cracks, etc. are likely to occur, carbonation phenomenon also tends to progress due to the porous structure, and deterioration progresses more quickly Is strong.

  Therefore, in the present invention, it is constructed at least at the boundary with the surrounding ground, and the top of the lower wall body made of soil cement is positioned below the level of the surrounding ground to avoid exposing the soil cement to the atmosphere and rainwater. In addition, it is possible to improve the durability by suppressing the progress of the deterioration of the soil cement and to maintain the strength of the soil cement over a long period of time.

  The lower wall body is a case where the high-concentration sludge treatment apparatus itself is partitioned from the surrounding ground and is composed of only the outer peripheral wall constructed at the boundary with the peripheral ground, and the outer peripheral wall and the outer peripheral wall according to claim 2. In some cases, the enclosed area is composed of partition walls that divide the area into a plurality of areas. In the case of claim 2, both the outer peripheral wall and the partition wall form a lower wall body whose top is located below the level of the surrounding ground.

  As the top of the lower wall is located below the level of the surrounding ground, the upper wall whose top is located above the level of the surrounding ground is placed on the top of the lower wall, for example, reinforced concrete. By using a material that does not cause cracks and deterioration, such as concrete blocks and concrete blocks, it prevents rainwater from flowing directly from the surrounding ground to the top of the lower wall, and improves the durability of the top of the lower wall. Suppresses the growth and deterioration of cracks caused by the wall top touching the atmosphere or rainwater.

  In particular, if leveled concrete or shade concrete is placed between the top of the lower wall and the upper wall as described in claim 3, the atmosphere to the top of the lower wall, which is a soil cement wall, Since contact with rainwater can be almost completely prevented, the durability of the top of the lower wall body can be further improved.

  Further, as described in claim 4, for example, the sludge treatment apparatus itself is treated by preventing the sludge treatment apparatus from leaking sludge and sludge, and the sludge water level in the sludge treatment apparatus is lower than the level of the top of the lower wall body. If the structure which can maintain the state located on top is used, it will be prevented that air | atmosphere and rain water contact a lower wall body top part in the use condition of a sludge processing apparatus, and durability of a lower wall body top part will improve more.

  As shown in FIG. 3, the soil cement wall constituting the lower wall is formed by overlapping soil cement columns constructed by excavating and pulling up with the rotation of the excavating rod 15 having the excavating blade 16 and the stirring blade 17. Constructed by the deep mixing process method (Claim 7) or by traversing the cutter post 18 with circulation of an endless chain 19 having a cutting blade 20 mounted so as to be circulated around the cutter post 18 as shown in FIG. It is constructed by a method of continuously forming soil cement (Claim 8), but by using the soil of the raw ground as a material, the material cost can be reduced in comparison with the reinforced concrete structure, and at least the lower part By eliminating the need for reinforcement work and formwork when building the wall, construction costs can be significantly reduced.

  Both the soil cement column constructed by the above-mentioned deep mixing treatment method (Claim 7) and the soil cement constructed by traversing the cutter post 18 (Claim 8) are excavating the original ground, excavating soil and cement. Or a cement-based material containing cement or a cement-based solidifying material is stirred and mixed.

  The sludge treatment device is constructed at least at the boundary with the surrounding ground, and the top is shallower than the depth of the lower wall of the lower wall in the area surrounded by the lower wall and the lower wall located below the level of the surrounding ground. It consists of a bottom constructed at depth and an upper wall constructed on the top of the lower wall, with the top positioned above the level of the surrounding ground, while the lower wall excavates the original ground and cement Or, it is constructed as a soil cement wall constructed by stirring and mixing a cement-based material containing cement or a cement-based solidifying material. Cement and a solidified material are generally used in a slurry state, but may be used as a powder.

  The lower wall is constructed at least on the outer periphery of the sludge treatment device so as to partition the sludge treatment device from the surrounding ground, but is similarly constructed as a partition for dividing the interior of the sludge treatment device into a plurality of tanks. Sometimes.

  The bottom plate prevents sludge and sewage from leaking out of the sludge treatment device, and the sludge treatment device itself has a structure that allows the sludge water level to remain above the level of the top of the lower wall as described above. In order to do so, a geomembrane is arranged as described in claim 5. In this case, normally, a geomembrane is laid on the abandoned concrete placed on the bottom surface of excavation, and unreinforced concrete or reinforced concrete is placed thereon as the bottom, but costs are reduced. Above, it is preferable to lay a geomembrane such as a rubber sheet that can follow ground deformation directly on the bottom of excavation, pour cement milk on it and place it by the self-leveling method.

  In order to prepare for the case where the supporting force of the ground under the bottom is insufficient, a soil cement column for supporting the bottom is constructed as necessary according to claim 6, and sludge caused by subsidence or deformation of the bottom is constructed. Leakage is avoided.

  In order to increase the bending strength and shear strength in the soil cement wall, core materials such as reinforcing bars, reinforcing bars, shaped steel, steel sheet piles, etc., are inserted after the construction of the soil cement wall and before its hardening. (Claim 9, Claim 10).

  Since the lower wall constructed at least at the boundary with the surrounding ground and occupying a large part of the sludge treatment equipment is constructed with soil cement that can also serve as a retaining wall, the material cost can be reduced compared to the construction with reinforced concrete. In addition, the construction of the retaining wall, the reinforcement work, and the formwork work in the case of building with reinforced concrete are not required, so that the construction cost can be greatly reduced and the sludge treatment apparatus can be constructed at low cost.

  In addition, by positioning the top of the lower wall below the level of the surrounding ground, it is possible to prevent the soil cement from being exposed to the atmosphere and rainwater. The strength of the soil cement can be maintained over a long period of time.

  In addition, rainwater flows directly from the surrounding ground to the top of the lower wall by building an upper wall on the top of the lower wall, which is a soil cement wall, with the top located above the level of the surrounding ground. Therefore, the durability of the top portion of the lower wall body can be improved, and the progress of crack growth and deterioration due to the lower wall body top portion coming into contact with air or rainwater can be suppressed.

  In claim 3, it is possible to completely prevent contact of the atmosphere and rain water to the top of the lower wall body by placing leveled concrete or shaded concrete between the top of the lower wall body and the upper wall body. Therefore, the durability of the top portion of the lower wall body can be further improved.

  In claim 4, in order to make the sludge treatment apparatus itself have a structure in which the sludge water level in the sludge treatment apparatus can be kept above the level of the lower wall body top, the atmosphere on the top of the lower wall body in the state of use of the sludge treatment apparatus. And contact with rainwater is prevented, and the durability of the top of the lower wall body is further improved.

  According to the fifth aspect, since the geomembrane is disposed on the bottom plate, it is possible to prevent sewage and sludge from leaking out of the sludge treatment apparatus.

  In claim 6, since the soil cement pillar that supports the bottom plate is constructed under the bottom plate, it is possible to compensate for the lack of supporting force of the ground below the bottom plate, and to avoid leakage of sewage and sludge due to sinking and deformation of the bottom plate. .

  In the ninth and tenth aspects, since the core material is inserted into the lower wall body which is a soil cement wall body, the bending strength and shear strength of the soil cement wall body can be increased.

  As shown in FIGS. 1 and 2, the present invention is constructed at least at the boundary with the surrounding ground, and the lower wall 1 (1, 2) whose top is located below the level of the surrounding ground, and the lower wall 1 (1 2), the bottom plate 3 constructed at a depth shallower than the lower end of the lower wall 1 (1, 2) in the region surrounded by 2), and built on the top of the lower wall 1 (1, 2), Cement-based material or cement-based material comprising an upper wall 4 whose top is located above the level of the surrounding ground, and the lower wall 1 (1, 2) excavating the original ground and excavating soil and cement, or cement This is a high-concentration sludge treatment apparatus using a soil cement wall that is a soil cement wall constructed by stirring and mixing solidification materials.

  When the lower wall 1 (1, 2) constituting the high-concentration sludge treatment apparatus 5 is only a single sludge treatment tank, the lower wall 1 is only the outer peripheral wall located on the outer periphery, FIG. As shown in FIG. 2, when divided into a plurality of sludge treatment tanks, there are an outer peripheral wall located on the outer periphery and a partition wall that divides a region surrounded by the outer peripheral wall into a plurality of regions (sludge treatment tanks). . Hereinafter, the outer peripheral wall is referred to as a lower wall body 1, and the partition wall is referred to as a lower wall body 2.

  As shown in FIG. 3, the bottom wall body is formed by overlapping the soil cement columns 1a, 2a constructed by excavation and pulling up with the rotation of the excavating rod 15 having the excavating blade 16 and the stirring blade 17 (deep mixing treatment method). A method of forming 1 and 2 will be described. As the excavating and agitating apparatus including the excavating rod 15, a single-axis machine or a multi-axis machine as illustrated is used.

  First, as shown in FIGS. 4- (a) and (b), the soil cement columns 1a and 2a having a predetermined depth are attached in one direction and overlapped with each other. (Outer peripheral wall) 1 and lower wall body (partition wall) 2 are constructed.

  The outer diameter of the soil cement columns 1a and 2a is generally 60 to 120 cm, but the wall thickness of the lower wall bodies 1 and 2 is determined by the width of the overlapping portion of the soil cement columns 1a and 2a in consideration of the water shielding properties. Therefore, the outer diameter is determined from the width of this overlapping portion. The length of the overlapping portion in the length direction of the lower walls 1 and 2 is suitably 5 to 30 cm, but 10 cm or more is preferable from the surface of the sludge that is stored inside the lower walls 1 and 2. From the viewpoint of economy, it is preferably about 20 cm or less.

  Since the depth of the high-concentration sludge treatment apparatus 5 is usually about 2 to 3 m, the soil cement columns 1a and 2a are constructed to a deeper depth. Although depending on the ground conditions of the construction site, the lower wall (outer peripheral wall) 1 also serves as a retaining wall, so its depth is determined so as to sufficiently withstand the lateral pressure shown in FIG. As shown by a two-dot chain line, the depth of the high-concentration sludge treatment device 5 is often built to about 1 to 3 m deep. The solid line in FIG. 2 shows the case where the depth of the lower end of the lower wall body 1 coincides with the depth of the lower end of a soil cement column 6 (described later) located at the lower end of the high-concentration sludge treatment apparatus 5.

  The soil cement column wall (lower wall 1), which is the outer peripheral wall, is a self-supporting mountain retaining wall as shown in Fig. 5- (a), so it is necessary to bear the bending moment due to the side pressure. If the column wall cannot resist the bending moment, the shape steel such as H-section steel 1b inside the soil cement column 1a as shown in (b), or the reinforcing bar or reinforcing bar as shown in (c) A steel core material such as の 1c is inserted. If the sheet piles as the core material are inserted while being engaged with each other, there is an effect of increasing the water shielding property in the lower wall body 1. Bamboo can be used in place of reinforcing bars in order to significantly reduce costs.

  5- (b) and (c), the centroids of the H-section steel 1b and the reinforcing bar 1c as the core are aligned with the center of the soil cement column 1a, but in use, one side of the lower wall 1 Therefore, it is reasonable to arrange the centroid of the core material close to the tensile stress side. 5 (b) and 5 (c), the core material is inserted into each soil cement pillar 1a, but one or two soil cement pillars 1a may be skipped and inserted.

  The soil cement column wall (lower wall body 2) that becomes the partition wall is constructed in the same manner as the soil cement column wall (lower wall body 1) that becomes the outer peripheral wall, but the bending moment that the outer wall receives on the partition wall is Since it does not become a problem substantially, it is also possible to omit insertion of a core material, and it is constructed in a simplified form from the outer peripheral wall.

  The area surrounded by the outer peripheral wall (lower wall body 1) and the partition wall (lower wall body 2) is excavated after the construction of the lower wall bodies 1 and 2, and the bottom board 3 is constructed to form a sludge treatment tank. However, in order to increase the supporting force when the supporting force of the ground below the bottom plate 3 is insufficient, it is supported under the bottom plate 3 as shown in FIGS. 1 and 2 in order to increase the supporting force. A soil cement pillar 6 is constructed. In FIG. 1 and FIG. 2, the soil cement column 6 is overlapped to form the soil cement column wall. However, since the purpose is to increase the supporting force, this is not always necessary. Sometimes build. However, when there is a purpose to increase the passive earth pressure shown in FIG. 5- (a), it is better to overlap like the soil cement pillar 6 shown in FIG.

  After the construction of the lower wall body 1 of the outer peripheral wall and the lower wall body 2 of the partition wall, the soil cement is cured until it develops strength, and then the region surrounded by the lower wall body 1 and the lower wall body 2 is The ground is excavated using an excavator such as a backhoe or manually to form a space for a sludge treatment tank. At this time, since the lower wall body 1 of the outer peripheral wall also serves as a retaining wall, excavation can be performed without taking any special countermeasure for retaining the mountain.

  Since sewage and sludge exudation from the bottom plate 3 or between the bottom plate 3 and the lower wall bodies 1 and 2 lead to environmental destruction, in the bottom plate 3 as shown in FIGS. 7- (a) and (b) Measures are taken to prevent sewage and sludge exudation. Here, the bottom plate 3 is constructed of unreinforced concrete or reinforced concrete, but a geomembrane 7 is laid under the bottom plate 3 such as a rubber sheet and a vinyl sheet, and can follow the deformation of the ground. As shown in FIG. 8, the geomembrane 7 is protected by placing concrete on the bottom panel 3 after water-proofing such as caulking 8 at the joints between the geomembrane 7 and the lower walls 1 and 2. While aiming, the bottom board 3 is designed to be sealed.

  If priority is given to the water-blocking of the bottom 3 parts, the geomembrane 7 is laid on the discarded concrete 10 cast on the cracked stone 9 as shown in Fig. 7 (a), and concrete or reinforced concrete is placed on it. However, in order to reduce costs, a geomembrane 7 that can follow the deformation of the ground directly on the excavated root cutting bottom is shown in order to reduce costs. A self-leveling method in which cement milk is poured on the laying is suitable. Even in such a case, if the water shielding treatment such as the caulking 8 is applied to the joint at the boundary between the geomembrane 7 and the lower wall bodies 1 and 2, the water shielding is more reliably improved.

  The surface on the sludge treatment tank side of the lower walls 1 and 2 is immersed in the sludge, so that it does not come into contact with the atmosphere, and the sludge is alkaline, so there is no problem of deterioration in durability due to neutralization. However, in cases where sludge may be temporarily discharged during regular inspections, or to improve durability, spray mortar on the surfaces of the lower wall bodies 1 and 2 or apply a protective material such as a resin coating. It is effective.

  As shown in FIGS. 2, 9, and 10, the lower wall (outer peripheral wall) 1 and the lower wall (partition wall) 2 are arranged such that the tops are located below the level of the surrounding ground to avoid exposure to the atmosphere. The upper wall 4 for preventing the inflow of rainwater from the surrounding ground to the sludge treatment tank is disposed on the top of the lower wall 1, and the adjacent sludge treatment tank is disposed on the top of the lower wall 2. Upper wall bodies 4 for preventing the inflow of sludge from each are constructed. The top of the upper wall 4 is located above the level of the surrounding ground.

  The upper wall 4 on the lower wall 2 serves to ensure the separation of sludge in the adjacent sludge treatment tank, and the top level of the upper wall 4 on the lower wall 2 is as shown in FIG. It is determined in consideration of the fact that the sludge water level in the sludge treatment tank is always higher than the top level of the lower wall 2 and the sludge water level in each adjacent sludge treatment tank may be different.

  The upper wall body 4 is mainly constructed of reinforced concrete or concrete blocks. In the case of a concrete block, as shown in FIG. 9, the top ends of the lower wall bodies 1 and 2 are formed, and the leveled concrete 11 is laid. Similarly, in the case of reinforced concrete, it is constructed after laying the leveled concrete 11, but it can be omitted. It is sufficient if the top wall level of the upper wall body 4 on the lower wall body 1 is about 20-30 cm above the level of the surrounding ground. However, from the standpoint of safety during heavy rain or to prevent falling. May be higher.

  Since the tops of the lower walls 1 and 2 may be exposed to the atmosphere due to changes in the sludge water level, the top walls of the lower walls 1 and 2 are protected to increase the durability of the tops and deteriorate due to weathering. In order to avoid this, as shown in FIGS. 10- (a) and 10 (b), cap concrete 12 that completely covers the top ends of the lower walls 1 and 2 is placed at the top ends of the lower walls 1 and 2. Sometimes. FIG. 10- (b) particularly shows that the reinforcing bar 1c inserted as the core material in the lower walls 1 and 2 is extended to the cap concrete 12 to improve the integrity of the lower walls 1 and 2 and the cap concrete 12. Indicates the case.

  After the construction of the lower walls 1 and 2, the aeration pipe 13 that sends air to the sludge in the sludge treatment tank and the weir 14 that moves the sludge between the adjacent sludge treatment tanks are installed, and the high-concentration sludge treatment device 5 is completed. To do.

  FIG. 1 and FIG. 2 show a state when the high-concentration sludge treatment apparatus 5 having six sludge treatment tanks is in operation. In the high-concentration sludge treatment apparatus 5, livestock dung is introduced into the first tank, and the livestock dung is introduced into the sludge treatment tank in advance by aeration. It moves to the next sludge treatment tank sequentially through, and is almost decomposed in the final tank. Residues left undecomposed are settled and disposed of.

It is the top view which showed the structural example of the high concentration sludge processing apparatus. It is a longitudinal cross-sectional view of FIG. It is the elevation which showed the mode of construction of the soil cement pillar by the excavation rod with an excavation stirring blade. (a) is a plan view showing a soil cement column wall, (b) is an elevation view of (a). (a) is sectional drawing which showed the soil cement pillar row wall used as an outer peripheral wall (lower wall body 1), (b) is a top view of (a). It is the elevation which showed a mode that a wall body is formed from the soil cement constructed | assembled by traversing with the circulation of the endless chain which has a cutting blade. (a), (b) is sectional drawing which showed the detailed example of the connection part of a lower wall body and a bottom board. FIG. 7 is a partially enlarged view of (a). It is an elevational view showing a case where an upper wall body is constructed by laying leveled concrete on the top edge of the lower wall body. It is an elevational view showing a case where an upper wall is constructed by placing a concrete cap on the top edge of the lower wall. It is the elevation which showed the processing method of the conventional high concentration sludge, such as livestock dung. (a)-(f) is the elevation which showed the process in the case of constructing a sludge processing tank with reinforced concrete.

Explanation of symbols

1 …… Lower wall (outer wall), 1a …… Soil cement pillar, 1b …… H-shaped steel, 1c …… Rebar bar
2 …… Lower wall (partition), 2a …… Soil cement pillar,
3 ... Bottom plate, 4 ... Upper wall body, 5 ... High concentration sludge treatment equipment,
6 ... soil cement pillar, 7 ... geomembrane, 8 ... caulking,
9 ... Written stone, 10 ... Abandoned concrete,
11 …… Fixed concrete, 12 …… Shape concrete,
13 …… Aeration piping, 14 …… weir,
15 ... Drilling rod, 16 ... Drilling blade, 17 ... Stirring blade,
18 …… Cutter post, 19 …… Endless chain, 20 …… Cutting blade.

Claims (10)

  Constructed at least at the boundary with the surrounding ground, with the top wall positioned below the level of the surrounding ground, and the depth surrounded by the lower wall body and shallower than the lower end depth of the lower wall body Constructed on the top of the bottom wall and the top of the lower wall, the top is composed of an upper wall located above the level of the surrounding ground, the lower wall is excavated soil and cement while excavating the original ground, Alternatively, a high-concentration sludge treatment apparatus using a soil cement wall that is a soil cement wall constructed by stirring and mixing a cement-based material containing cement or a cement-based solidifying material.   The lower wall body is composed of an outer peripheral wall constructed at the boundary with the surrounding ground, and a partition wall that partitions the region surrounded by the outer peripheral wall into a plurality of regions. Concentration sludge treatment equipment.   The high-concentration sludge treatment apparatus using the soil cement wall body according to claim 1 or 2, wherein smooth concrete or shade concrete is placed between the top of the lower wall body and the upper wall body.   The height using the soil cement wall body according to any one of claims 1 to 3, wherein the sludge water level in the sludge treatment tank can maintain a state of being located above the top level of the lower wall body. Concentration sludge treatment equipment.   The high concentration sludge processing apparatus using the soil cement wall body in any one of Claim 1 thru | or 4 with which the geomembrane was laid in the bottom board.   The high-concentration sludge treatment apparatus using the soil cement wall body according to any one of claims 1 to 5, wherein a soil cement column that supports the bottom plate is constructed under the bottom plate.   The soil according to any one of claims 1 to 6, wherein the lower wall body is formed by overlapping soil cement columns constructed by excavation and lifting accompanied by rotation of a drilling rod having a drilling blade and a stirring blade. High concentration sludge treatment equipment using cement wall.   7. The soil cement wall according to claim 1, wherein the lower wall body is formed continuously from a soil cement constructed by traversing a cutter post with circulation of an endless chain having cutting blades. High concentration sludge treatment equipment used.   The high-concentration sludge treatment apparatus using the soil cement wall body according to any one of claims 1 to 8, wherein a core material is inserted into the lower wall body.   The high-concentration sludge treatment apparatus using a soil cement wall body according to claim 9, wherein the core material is steel.

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